Percussive tool.



.ferner omino CHARLES lH. HAESELER, G1? HEQDELPHA, PENNSYLVANIA.

FERCUSSVE TOOL.

Appliction filed March. (i.

To fiti :riiom if may concern lie it linown that l, CHARLES ll'. llenasin, :t citizen of the United Sintes o. America, ind at 'resident ofPh'ilnddphin, county'ol Phihidelphiin und' Siate ol Pennsylvania, haveinrented certain new nnduseful Im- 'prm'einenls in Power-OperfitedPercnssive tonie, of which the following is; :i speciticiitioinretifreoce being had to the siccomofifiii'ing drawings, forming :iportthereof. invention relates to power operated 'e tools such :inlrockt-drills, mining es, power lnnmnews, pile drivers, and the ihre, theoperation :it which is effected by elastic nii-tive fluid unl-.lerpressure alterniitey admitted into o. r-oilting cylinder 'noon oppoiiesides ot'- ii ieeipri-icoting piS- ton *freely inonntefl therein. ln n{1o-pending opp: intimi. Sei-inl Nnniher 5785149, tiled ngnsigth, Ulli),i hzivf: disclosed :i novel ineens fior cushioning; the working pistonupon the return stroke, together with means for augmenting ine 'torce ofthe blow imported upon the Loi-word or working' stroke, Siieh means notonly tending'to increase the sioeed4 of n'iovenient of the piston 'ontto deei ose the :nnonnt of .oiotivehiid conmned; and my presentinvention relates to :i specie construction et i'neclmnism adopted toeffect this'refsuli'-y In order that my invention may "oe thonr onphlyimdcretiiod'l will now proceed to describe en ei'iihmliinent tl; mf.,heying refe@ ence to the zicconipimyinlv1 ili'owiwjs iiluS lti'zitingthe Sanne, und wili il" point ont the novel features in Cini osi.

@in the drewinge: lfig'n're 'i' is ai View in central longitudinalsection of a power rock drill constructed in ziccordanoe with myinvotation.4 lfig. and il are respectively views inside and endelex'zitiono a nut empioyed as. a partei ille rotating mech- :ioiinthereof.,

-ho roch drill illuetrizfted eoinprises in ,c'eneri'ih :t mein workingcylinder 5, o te# procnting'piston 6 thes'ein, :L distributing valve ifor admitting zindexhausting motive fluid to rind. `:trom the cylinderbelow ind above the, iiiieton, and' rotating mechanisn'i by which step'by step movements of rotation 'are imparted to the piston The valve Zis of the piston type and is operated by ffioid pressure inone'direction or the other l t about the time the piston regiones ehi.itsfstr ,he in either direction Speccetion of Letters Patent.

ymode in one part, und such n construction y Ithe rifle bar to thepiston.

Patented Feb. 18, 19,13,

ieu. sei-iai no. 512.136.

'lflie rotating mechanism comprises a ril'le har S secured :igrninstrelative longitudinal movement in the upper head 9 of the drill,rolf-het undl piiwl mechanism l0, by which moven'ients of rol'iiiion ol'the Snidrifle bar ire permitted in one direction hut prevented in theother. und :i init Il secured in the upper end ot the piston (S andfitted to tho said rifle our.

'The piston (3 hasn (,fylindrienl cavity 1Q therein which receiver:` theforward end o'. the rille hor 8. und the said forward end of the. ritlehair hns otlixed thereto or fornied :is n part thereof. ii small piston13, which is fitted 'lo the said cylindrical cavity l2 is will rodily beseenl by reference' to the drawing; It the pieton l: he inode reinoi'-nhle from the rille har, the, not ll maybe is shown in the co-pendingapplication above referred lo, hut .ihere the piston is inode :is a portof the rille hair it' is conrefr ient tof'mnhe the mit l1. in two partsc :shown in Figs. Qdi-nd 3 ot the'drnwi wherein to 'facilitate theassembling and issemhliige of the parte. Then .titted into place the nut11. is reinforced by the walls of the piston' mid the feet that it ismode in two halves is thus innnateriol in the normal. operation'ot thetool.

in the normal operation ofthe tool, niotiio fluid.I such :is oir orsteam under prossiirm li'r admittedbehind the innin piston to more theSonie' forward, the working epilee in the mein cylinder in front of themoin pisslon being atv snob u time opened to exhaust, then as thepistonv reaches the end ot' its forward stroke,` motive fluid is adniittedin front of the, piston to drive the sinne backward,the'previously employed ,motive fluid at. theloack of the piston heine:then permit-ted. to pass to the exhaust. in the forward movement of thepiston the ratchet and pnwl mechanism -10 permits the rifle bnr 8 torotz1te,'tlie same being given n movement of rotation tl'ironghont :iportion of a r xvolntion by menno of the coziction of the inclinedgrooves therein with the complementary projections in the mit 11,\vhileupon the' rearward or return movement of tho piston G the ratchet andpziwl mechanism holds the ritle bar stationary and n :irtial movement ofrottion is imparted Near its foi-wordend thefmain piston 6 is providedwith' a cu'cumforentlal anniiiar groove or recess 14, the'rear end ofwhich 1s 1n open communicatlonthrough a cross passage with the interiorof the cylindrlcal cavity 12.- Tlns recess is arranged toi come intoregister with a cross passage 1G arranged in-communicat'ion with themain forward admission passage 17, whereby as the main -plsto r 1reaches the end lof'its Aforward stroke motlve-fluld `under pressure'will be admitted from the said admission .passage 17- to the interiorof the cylindrical cavity; rlhenas the main piston commences its.rearward movement the piston .will move out of registry withthe saidcross passage '16 and during the entire remainder of the rearwardmovement of the piston the interior'cavit-y 12- of the pistone 'will-beentirely closed. The motive fluid thus admitted to fill the cavity 12-when vthe piston isin-its forward position'will be entrapped during the'rearward movement thereof, whereby this motive fluid will bev graduallycompressedv during substantially vthe entirerearward movement of thepis'- ton and will act as an etlicient cushioning means to prevent thepiston from striking the upper head 9. It will, of course,'be

understood that the effective working area ofthe fluid on the front endofthe main piston is considerablygreater than the arca of the cavity,-`so that 'there will be plentyl of .power to move the piston backwardwhile at the same time compressing the entrapped motive fluid inthecavity 12;,'and' in addition it will be appreciated that'in operationthere 'isa considerable rebound to the .main pistonffollowirig' theimpact of thedrill upon the rock, the momentum ac? quired in .suchrebound acting to augmentthe-action of the motive fluid in effecting thereturn 'movement of the piston. Then the piston has `reachedthe-.limitof its rearward movement' and motive fluid is admittedabov'eit e'. e. to the rear thereof to again effect a forward movementof the'same, motive fluid; atsuch time 4being exhausted from lin front ofthe'piston, such forward movement l'of the piston will be augmented andaccelerated -by the energy contained in the fluid compressed as it is toa high degree in the cavity 12. As the piston 6 moves lforward and themotive fluidv contained therein expands it will be noted thattheoretically such expansion will be only to t-he pointof pressure `atwhich the inotive fluid is employed. -Actually in. `practice there willbe a slight loss due to leakage and..

it is only this loss which has to be resupplied each time the piston' (3reachesthe forward extremityI of its stroke. F or this reason theduration of time within whichthe 4groove 1l and the cross passagel'arefin registry, may he very short;I moreover the cross passages 1Gand 15 may be verysmall in cross-sectional area.

degree of compression of the tive -fl'nidf within the cavity l2 is verygreat,l`

--1 have-provided the piston` with an mtertooll'ithe' combination withamain cylinder,

and -a percussion piston lfreely mounted therein and having acylindrical cavity lprojecting inward from the rear end thereof, ofacushioning pistonmounted in the. cy-

lindrical cavity, and held against' longitudinal' movement relative tothe cylindcr 1nd means for admitting elastic motive Huid under pressuretothe cylinder, said'cylinder and piston being provided with ports andpa ssa ges arranged to come into register to admit the motive fluid tosaid cylindrical cavity when the piston is near the end of its forwardstroke, 'and to be out of such registry, so

Vthat the lmotive fluid s'o admitted will be entrapped in such cavity,in positions of sald pistonother than near such end of its stroke. .2.In an elastic fluid operated percussive tool the combinationy with amain cylinder and a percussion piston freely mounted therein and havinga cylindrical cavity projecting inward from one end thereof, of acushioning piston mounted in the cylindrical cavity, and held againstlongitudinal movement relative to the cylinder, and means .for admittingelastic motive fluid under pressure to thefront end of said cylinder,said percussion piston and cylinder having complement-ary passages forconnecting said cylindrical cavity with the forward end of the cylinder,arranged to come into register as said percussion piston nears theend`ofits forward stroke, and to pass out of registry as said piston commencesits return stroke, so that the motive lluld'in said cylindrical cavitywill be entrapped therein,

and further compressed 'during substantially the entire return movementofthepercussion iston.

3. n an elastic fluid operated percussive tool the combination with amain cylinder, and -a percussion piston freely mounted therein andh'avng a cylindrical cavity projecting inward from one 'end thereof, of'a cushioning pistoni mounted in the cylindrical cavity, and heldagainstlongitudinal move- [ment relative to the cylinderand. means foradmitting elastic motive 'fluid un'der presl sure to the `front end ofsaid cylinder, said-percussion p'stolr having an annular circumferentialgroove therein and a pas-v sage connectin'g said grove with said cylindrical'cavity, and said cylinder having a motive fluid admissionpassage, arranged to come into register `with said groove as the pistonnears the end of its forward stroke, whereby said motive fluid will beentrapped in said cavity and compressed therein during the returnmovement of said piston, l y v 4f. In a rock drill the combination witha main cylinder, and a percussion piston freely mounted therein andhaving a cylindrical cavity projecting inward from the` rear endthereof, of a bar carried by the rear head oi' the main cylinder andprojecting forwardly into said cylindrical cavity, a piston carried bythe forward end of saidbar and fitted to said cylindrical cav-y ity, andmeans for admitting elastic motive iiuid under pressure to the cylinder,said percussion piston and cylinder having complementary passages forconnecting said cylindrical cavity with the forward end of the cylinder,arranged to come into register as said percussion piston nears theend ofits forward stroke, and to pass out of registry as said piston commencesits return stroke, so that the motive Huid in said cylindrical cavitywill be entrapped therein, and fursubstantially the ther compressedduring of the percussion entire return movement piston. e

5. In a rock dri-ll the combination with a main cylinder, and apercussion piston freely mounted therein and having a cylindrical cavityprojecting inward from the rear end thereof, of a bar carried by therear head of the main cylinder and ,projecting forwardly into saidcylindrical cavity, by the forward end of said bar and fitted to saidcylindrical cavity, and means for admitting elastic motive yiiuid underpressure to the frontend-of said cussion piston having an annularcircumferential groove 4therein and a passage con* necting said groovewith said cylindrical cavity, and said cylinder having a motive Huid'admission passage, arranged to come into register with said groove asthe piston #nears the end of its forwardstroke, whereby saidmotive fluidwill be ent-rapped in said cavity and compressed therein during thereturn movement of said piston.

CHARLES H. HAESELER. Witnesses:l p

D.4 HOWARD H AYwooD, LYMAN S. ANDREWS, Jr.

a piston carriedcylinder, said per v .I

